You've heard of Burger King. Prepare for Burger Queen. Now in its second year, the beauty pageant with a difference is the brainchild of 27-year-old performance artist Scottee, a "second-generation fattie" who wants to challenge the stereotype of fat people as "broken and unhappy". Burger Queen takes place throughout March at the Royal Vauxhall Tavern in London.

It has four heats, each with three rounds: trend, taste and talent. Creativity is prized above all. For the fashion round, contestants make their own outlandish outfits. All the contestants are non-professionals, many performing for the first time. Winning last year's event was definitely a confidence-booster for Nina Neon, a Swiss postgraduate who uses a wheelchair and sees similarities in the stereotypes of fat and disabled people: "People assume that you're not healthy or happy. Burger Queen helped me to see that, as long as I am happy, weight doesn't matter."

This combination of serious message and light-hearted presentation persuaded head judge Amy Lame to get involved. "In this economic climate, fat becomes a moral issue: 'Why aren't you controlling yourself?' The government purports to be interested in our health, but they're just telling us to lose weight, not tackling the psychological issues behind why people may be fat."

Like Susie Orbach, Lame argues that obesity, class and economics are interlinked: the less money you have, the more likely you are to shop cheaply, which invariably means buying high-fat, high-sugar foods. And nowhere are obesity and economics more closely linked than in the diet industry, which, she claims, "is geared towards not making us lose weight but making us dependent on their products". As part of Burger Queen, Scottee will be screening four films, which document his experiences on various diets. On Slim-Fast, he lost five pounds – but suffered headaches. His medical advisor — "an NHS doctor who is pro-health every size" — reassured him that headaches commonly result from starvation.

Two things have surprised Scottee about Burger Queen so far. One is the reluctance of "fat celebrities" to join the judging panel: "Maybe they think it's bad PR," he speculates. The other was the number of entrants to last year's contest who were not plus-sized. At first, Scottee thought they had missed the point. "Then I thought: how fantastic. To identify yourself as fat is to identify as the outsider. Fat is a liberation politic – and anyone who understands that is welcome to join our chubby gang."

Burger Queen is at the Royal Vauxhall Tavern, London SE11. Tickets from burger-queen.info